China’s Chang’e-4 Probe Makes Soft Landing on Far Side of Moon
China’s Chang’e-4 probe has made history by achieving the first soft-landing of a spacecraft on the far side of the Moon, which always faces away from Earth.
To communicate with ground stations, Chang’e-4 relies on Queqiao, a relay communication satellite that orbits a point behind the Moon and bridges Earth and Chang’e-4 and depict the future of lunar relay communication systems.
But how does Chang’e-4 probe communicate with the Earth? The answer is Queqiao, a relay communications satellite, explains Lihua Zhang from DFH Satellite, China.
As explained by Zhang in a review paper recently published in Space: Science & Technology, Queqiao is an unprecedented satellite designed specifically for one purpose: to act as a bridge between Chang’e-4 probe and the Earth.
“Scientists in both China and other countries have conducted analysis and research based on the retrieved data, and they have produced valuable scientific results. The longer the operational life of Queqiao, the more scientific outcomes will be achieved,” remarks Zhang. Based on current predictions, Queqiao should be operable on mission orbit for at least five years.
Zhang also addressed the prospects for future lunar missions and how to relay communication systems should evolve to support them.
Many unexplored areas on the Moon, such as the largest crater at the South Pole, call for multiple relay satellites to maintain constant communication links, which poses an expensive and time-consuming challenge.
But what if relay satellites were suitable for more than a single mission? “A sustainable communication and navigation infrastructure should be established to benefit all lunar missions rather than dealing with each mission independently,” comments Zhang, “This infrastructure should adopt an open and extensible architecture and provide flexible, interoperable, cross-supportable, and compatible communications services, which are critical to the success of future lunar explorations.”
Future endeavors on the far side of the Moon will likely be a test on how well we can cooperate to unveil the secrets of our natural satellite.
